package com.gitee.cliveyuan.tools.web;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;

/**
 * ip 工具
 *
 * @author clive
 * Created on 2018/07/30
 * @since 1.0
 */
public class IpTools {

    private static final Logger logger = LoggerFactory.getLogger(IpTools.class);

    /**
     * 获取访问者ip
     *
     * @param request
     */
    public static String getClientIp(HttpServletRequest request) {
        try {
            String ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if ("127.0.0.1".equals(ipAddress)
                        || "0:0:0:0:0:0:0:1".equals(ipAddress)
                        || "localhost".equals(ipAddress)) {
                    return "127.0.0.1";
                }
            }
            //对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) { //"***.***.***.***".length() = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
            return ipAddress;
        } catch (Exception e) {
            logger.error("getClientIp Exception", e);
            return null;
        }

    }
}
